My brother was messing with my new 4S and asked me how secure the phone was if I lost it. I explained how I could lock it and track it down should I lose the phone. Low and behold, Siri will display your information when locked with a passcode. Ask her "who am I" and who ever stole your phone has all of your information. I tried to see if there were any settings where I could change this but the only setting I could find was to disable Siri while locks. If anyone has any suggestions, please let me know.